Fluid-heating system



Aug. 18, 1925. 1,550,437

w. s. HAVEN FLUID HEATING SYSTEM Original Filed Feb. 16, 1920 2 Sheet 314094@ kof,

Patented Aug. 178, 1925A.

s. H'A'v'iiN,l 'or RACINE, WIscoNsiN.

' FLUID-HEATING f SYSTEM.

Appiicatimi inea February-16, 1920, serial No.-35sl,s11. fnene'wea Janmary31,`- 11925.

Tof @ZZ fio/0m t may cof/warm: y

Be itknoivn that I, WALTER S. HAvEN, a

citizen of the United Statesof America, and

' lresident of Racine, Racine County, State of iViscoiisin, have inventedy certain new and useful,Improvements inl and Relating to Fluid-Heating Systems, of which the following is a specification This invention relates to certain improvements lin fluid heating apparatus;- and the objects and nature of the invention Will be readily un-derstoodby those skilled in fthe art in thei light of the following eXplanaf tion of the Yaccompanying drawings illustrating WhatInoW believe to beftlie preferred embodiment or mechanical expression of my invention from among other forms, 'constructions, arrangements, and combinations within the spirit and scope thereof.

An-'object er ftlie' invention is to provide improved means iii^(s1orc`alled) va'cu-umfluid heating systemsvihereby a'partial vacuum ismaiiitained in the radiator system'by the v'aciuim'fcreating action of a 'bodyof fliqui'd descending-in ay closed conduit and repeated` lv used to reduce'ivaste of theliquid;

A' fiirtliei---object of `tlie invention istoA provide' fluid lieatiiig'systeni inavvliiehf a parti-al-vacuu`m pullis exerted upon the fradiators by a column ofl liquiddesceiiding through' a series ofclosed'chambers arranged at diffrent elevations the liquid periodical-v ly filling and being" drained from oiie v'chainber to -tlie neXt lower' yone by positive*v gravity action.` i

A further object of tlieiiiventionis to pro: vide improved'valvevmeohanism for a closed eliai'nlier in communication withthe radiators or" a'. liuidheatingu system, whereby the chamber Willlbe periodicallyy iilled and lemptied with a'liquid,` to create a pressure `redueing and air efrpelli'ng fiction in thecliam-` ber which ivill cause a' partial Ivacuum pull flosed chamber to another to successively fill said chambers for expelling air therefrom radiators of a fluid heating system.

xA further'objectl of theinventionu is to any preferredl heat radiators conneeted With and then -to successively drain said chambers to produce a partial vacuum acting upon the and periodically filling-and draining-#a tank by improved float valve zmeehanis -A further objectfof the linventionristo provide a fluid 'heating' systein having liquid actuatedlmeans f for: inaintainingia @partial vacuum in the radiators, "with improved au#j tomatic meansforfstoppiiigand starting the liquid 'supply to thefvacuum creating ymeans at predetermined pressures 1in :the radiators, above` and belovv `atmospheric pressure for example. f

:A' t`urfther object of 'theinvention is lto provide i an improved pressure `regulator comprising means for automatically opening or' closing a? v'alve controlling thefpressure" creating means, according to spredetermined variations in the pressure.

A `further object of the invention ist provide a fluid heating system' arranged Ifor a partial" vacuum fp'ull through"tlier'adiators of thesystennwvherein as the steam is shut oli' from a radiator, the vaci'iiim'pull is also shi'it off therefrom.,

.iulfurtlierobject off-the invention is'toy provide certainfiinprovements in combinations orpfarts, and features of V'construction and arrangement asimore 'fully and particularlyset-foith hereinafter, with theeii'd in view' of 'producing a highly eflioient and] advanta geoiis1 flu'id heating system. l Referring ito the'f'accompanying draw` ingstg- Fig. lf is af' diagrammatic illustration of my improved-steam heating' system.

Fig;r Qis' Idetail vertical 'section through one or' the"drainag'e' tanks 'showing valve meehanismwhioh may be :employed therein.

E 3 Yis a detail ,vertical section through the' pressure regulating mechanism` for automatically controlling the liquid supply;

"Figjll is a detail elevation of a radiator illustrating means that might be employed for Closing the pipe at the discharge end of the'iadiator aslthe steaiiipipeat tliejlop# posite 'endof'the radiator is closed.

Fig. 5, is a detail vertical section illustratiiigmea-ns for closing a radiator from the air 'pipe line. y

Portions of tlie'radiators ofitlie radiator system of a steam or vapor heatingsyst'eim are shown ,at l, these radiators `being"mere'ly diagraminatic'ally illustrated Fto 'indicate afsteainl generator in -`such"maiiiier'that a partial vacuum created in said radiators is communicated to said generator to draw steam or other hot fluid therefrom into fthe radiators and to expel dead air from the radiators in advance of the hot vapor or other heating medium.

The radiators are shown as each provided at one end with a steam pipe 2, which pipes are in communication through any suitable pipe line with a steam generator not shown. At the opposite end of each radiator is provided an air pipe 3 to receive the air from the radiators and through which a partial vacuum pull may be maintained through the radiators, these air pipes communicating with a suitable pipe line 4, diagraminatically illustrated.

The steam pipes 2 and the air pipes are provided with suitable eut-off valves and 6 respectively, and mechanism which will be hereinafter more fully described, is

DI O3 l preferably provided whereby closing of the is not in use and thereby reduce leakage into the air pipe by cutting off dead radiartors.

The air pipes of the radiators may also be provided with any suitable arrangement of check valves to prevent back flow of air into the radiators, and with thermostatie valves to prevent outflow of steam from the radiators, and the pipe line to which said air pipes connect is provided with a final air discharge to atmosphere equipped with means to prevent baek flow of air.

Between the radiators and said final air discharge to atmosphere, the air pipe line is provided with means for producing a partial vacuum in said line and the radiators. comprising` a series of tanks, compartments or other chambers to be successively filled with liquid to force air from such chambers to the next lower one. andV to be successively drained from one to the other, under such conditions as to create a partial vacuum therein and thereby exert air exhausting pull through the series of tanks and the air pipe line on the radiators.

In the particular example illustrated, I show a vertical series composed of any suit able number of elevated closed tanks, chambers or compartments 7 9, l0, arranged in different horizontal planes, so that liquid will flow from the highest tank 7 to the next tank S below, and so on down from tank to tank throughout the series, so that each tank will be successively7 filled and emptied.

A pipe l1 extends through this series of tanks from the top of tank 7 to 'the bottom of tank 10, and above tank 7 it is suit-ably connected to a pipe 12 of the air pipe line.

The pipe 12 is in open communication with pipe ll for free flow of air fromthe pipe line into the tanks by way of pipe ll, but is closed against back flow from pipe l1 to the air line by a check valve 13 in pipe 1l above the uppermost tank.

Any suitable means may be provided for supplying water or other liquid to the series of tanks for carrying on the partial vacuum producing action resulting from the successive filling and emptying of the tanks. For this purpose, l show a water supply pipe lll, from any suitable source of water under pressure (such as a municipal water supply system) from which water is supplied for maintaining a normally approximately constant flow of water into the uppermost tank 7 suitable valve l5 is provided in pipe i4 for automatically shutting off and controlling the rate of flow of water into the tank system through this pipe as will be hereinafter fully explained.

The pipe 1l extending through the tank series is arranged below the lowermost tank, for the discharge of air and liquid from the series of tanks, as shown at 17. This discharge to atmosphere preferably constitutes the final air discharge or outlet to atmosphere for the entire air line from the radiators, and also forms a water discharge to atmosphere. This out-let to at inosphere is provided with any suitable means to prevent admission of air to the drain pipe. shown in the present instance, as a liquid seal 1S through the medium of which the air and water in the drain pipe are discharged to atmosphere, the water overflow from the liquid seal passing to any suitable drain or oflitake (not shown). The pipe ll adjacent its outlet end is preferably provided with a freely downwardly opening cheek valve 19, to prevent upfiow of water from the liquid seal under conditions that might possible arise.

.ln tbe example illustrated.` as thus far described. the air line from the radiators includes pipes ll and l2, as well as the series of tanks. as the. air flows therethrough on its way from the radiators to the final discharge to atmosphere at liquid seal 18.

Each of the tanks of the series is provided with suitable means to prevent drainage of liquid from the tank while the tank is being filled and the air is being` expelled therefrom, and to start the operation of draining the liquid from the tank into the next lower tank or inte the water seal 1S, when the tank has been filled with liquid, and by this draining or emptying process to create a partial vacuum in pipe 1Q. The means l prefer to employ to close the drainage outlet from each tank when the liquid has been drawn therefrom, and to open the drainage outlet and start the downfiow of liquid from the tank when the latter has been filled are automatic in action. Each tank will thus be periodicallyautomatically filled and thenemp tied, the liquid passing down successively from tank to tank, and, each tank as it is filled discharging lair into the next lower tank, until the airis iinally discharged kto the atmosphere'through liquid seal 18, and each tankas itis emptied drawing air `from the nextV upper `tank until the uppermost tank is reached, which latter drewo the air fromgthe air pipe line and the radiators to create a partial Vacuum therein.

In `the present exemplification ofmechanismyfor performing these operations,l show each of the tanks `as providcdwith an approximately central transverse partition 2() dividingthe tank into two superimposed closed chambers 21, 22. Thepipe 11k where it passesthrough this partition is provided with a suitable closure plug 23 forming noncommunicatingsections lli*- and llbof this pipe in chambers 21 and 22, respectively. The pipe section 11a is in open communication/with chamber 21 adjacent the top and bottom of -said chamber, for instance, through the medium of perforations 24 and 25 at its `upper and lower ends,respectively.

rflhe pipe section 111 is in communication at its upper end with chamber 22, through suitable perforations 27,in said pipe section. An ,additional drain from chamber, 22 to pipe 1l is alsofprovided by meansof a pipe 28 extending fronithe bott-om .of the tank into pipe 11v at apoint in said` pipe below the tank. Thisdrainage pipe is provided with a suitable Heat-controlled; valve for opening or closing thedrain, as will be hereinaftenmore fully described. Y

In order to prevent excessive noise, due to the air and water flowing in the` pipe when the system is in operation, a Ymuiler is preferably provided for pipe 11, shown in ther present instance.r as a pipe 29 surrounding pipe 11L in spaced relation and extending the` full height of chamber 21. `This pipe is in communication with chamber 21; through suitable perforations and 31 at its base and upper endl respectively. The connection between the water supply pipe 14 and the luppermost tank of the series, is exemplified yformed at the port in the bottom of the com-` partment which leads into pipe 28, `This valveseatis shown as a tapered valve seat 35. The valve 34is adapted to close down f on the seat to prevent flow from compartment 22 sometime before compartment 21 begins to overflow into compartment 22, and is adapted to rise from the seat and permit the flow from compartment 22 after compartment 21 has nearly completely emptied into compartment 22, and tort-his purpose the valve is shown as controlled by a float 36 in compartment 21. .l j

Exemplifying this arrangement, the valve may be provided with lan upwardly extend ing stem or valve rod 37 extending through partition 2O into compartment 21. The valve rod is preferably surrounded by a guide pipe 38 extending from the upper part of compartment 21 to any desired depth into compartment 22, andsaid guide pipe maybe provided with air vents, shown as perforations 39, just below the partition 20.

rin operating vconnection is kprovided `between the float 36 in compartment 21 and the valve rod 37, which connection may comprise a lever40 secured to the float and fulcrumed in a suitable bracket 41, and having a link connection 42 with said valve rod, the parts being` so arranged that liftingof the iioat will seat valve 34 and dropping of the float will raise the valve from its seat.

The float is of such size or liftingpower, that it will lift and seat valve' 34 when the liquid in compartment 21 Areaches the level ofL the float,and the float is preferably ari compartmentmay` be provided in addition to guidepipe 38, such an additional means being providedby an overfiow pipe 43 having its open upper end arrangedin the upperpart ot compartment v2140i the tank, and its lower discharge end arranged .adjacent the bottom of compartment 22 of tlietank.k

in operation, the upper compartment oi? a tank is first filled, in the case oft the uppermost tank, through. pipe. 32 from the water supply, and in the case oi `one of the lower tanks through the perforations 24and25 in pipe l1 which for is a continuation of the drain 11b of the'next upper tank. As the water rises in the compartment float 3G is soon reached, thus closing valve 34 and prepa-ring compartment 22 to hold water. The air'in compartment 21 is driven ahead ot the water rising in the compartment and is therebyT forcedthereiirom into compartment 22, throughgaide pipe 38 and overflow pipe 43, and when compartment 21 is nearly filled andthe watentherein reaches the level ofthe upper ends otsaid guide pipe and overflow pipe, the water will overflow il overflow pipe coiriai'tniein, to il into the low-e. and drive the through the pei iorations in pipe thence into the next lower tank and ultimately to the atmosphere.

As the overflow from compartment 2i lille compartment 22, means are provided 't i.' ultimately opening the upper compartment directly into the lower, so that the accumulated liquid in the upper compartment will rush into the lower, approximately completely fill the latter and drive all of the air thercifrom through pipe lll.

For this purpose, a port is provided in partition for the flow of liquid :from the upper to the lower compalti'ont, and this port is surrounded by a preferably tapered valve scat The i'low of liquid thi'oiiigli this port from compare-,neat 2l is controlled by a suitable valve shown as a taperin g valve adapted to close dovi'n on the valve seat to prevent flow into compartment 22 'trom compartment 2l through. this port when compartment 2l and afterwards compartment 22, are filling, and adapte-fl to risc 'l `i i')l'll the seat and permit the iiow after compartment 2l is filled, and compartment 22 has been nearly filled, to rapidly complete the lling of the lower compartment from the upper.

As a means for accomplishing this result, the valve 45, if so desired, can be provided with a depending stem or valve rod extending into compartment 22, to the lower end ot which is pivoted a rod il?, as shown at e8, one end of said rod being pivoted through the medium of a suitable bracket to the wall ot the tank as at 4:9, and the other end of the rod having a float 50 fixed thereto, the Vfloat being oit such specific gravity and the parts being so arranged and positioned in the lower compartment of the tank, that when said compartment is nearly filled with water, the float will be raised by the liquid to open valve lo and permit free flow from the upper compartment into the lower, and when the water has been discharged from the lower compartment to such an extent that its level is below the float, the latter will drop, and close valve 45, thus preparing the upper compartment for refilling.

By the mechanism as thus far described, it will be seen that the upper compartment of a tank is first filled. the lower compartment at the same time being made ready to hold water by the automatic closing of the valve in drain 28, and the air in the upper compartment will be forced into the lower. Vhen the upper compartment is filled it will overflow into the lower and as the latter is filled the air therein will be forced out through pipe 1lb into the next lower tank and finally to the atmosphere. The coinplete illing ot' the lower compartment is accomplished by the opening of valve to permit the water in the upper compartment to rush rapidly into the lower compartment to fill the saine, and by the rapid downrush of water to draw air therewith from the upper compartment and also draw air into said compartment from pipes ll, 12 will cause air to be drawn into the same through openings 2l and 3l, from the next upper tank of the series or from the air pipe line. T he final draining oi' the lower compartment to torni a vacuum in the latter, is accomplished by the automatic opening ott drain 28 at the bottom of' said lower compartment. Thus it will be seen that the upper and lower compartments oit each tank are arranged to successively till and drain, thus successively creating a vacuum in the upper and lower compartments to exert an air exhausting pull upon the next upper tank and finally upon pipes l2 and Ll and the radiators of the system. t the same time the liquid in the tanks is successively drained into the :next lower tank to repeatthe vacuum creating operation therein, and the air in the tanks is successively forced into the next lower tank until the air and liquid are finally discharged to atmosphere at t-he lower end of pipe 1l.

During the normal operation ot' the apparatus, the valve is open and water is constantly flowing into compartment 21 through pipe S2, except when pressure in the air pipe line closes the water supply through valve l5 and its pressure actuated controlling means. r'he water supply to pipe 32 is cut oft so long as the pressure in the air pipe line 3, l, l2 is sufficient to actuate the lever 5S against its adjustable weight to close valve 57. then the valve 57 is closed, whatevir water previously delivered to the tanks 7, 8 etc. and remaining therein travels down through the saine if sufficient in volume to operate the valves, Yfunctioning as herein described, and is finally discharged at 1T. The rate of flow oi" water through pipe into compartment 2l is controlled by valve 33. The flow through pipe 32 is relatively slow with respect to the rapid outflow through the discharge controlled hy valve The valve is set to cause the. con'ipartment 2l to fill in a predetermined length of time, say for instance, every ten minutes more or less, whereas the compartment is emptied very rapidly say in fifteen or twenty seconds, when the valve el is raised. The down flowing` water passing through the single pipes ll joining` the tanks 7, 8, etc. drags or sucks the air from above and acts as a check valve in preventing back fiow of air :from a lower tank to an upper tank. The air is carried down with the water through these single pipes but the air cannot flow upwardly in said pipes against the descending water, hence l do not find it necessary water pipe 11.(from bran-cli 28) isdraw ing air through pipe 11b,- -perforations 23, chamber 22 (above the water level)I and from compartment 2li-(above the-waterY level) through periorations 89V and pipe 38. By the time compartment 22 Aisempty, the slowly rising water in compartment 21 will raisefloat 376 and close discharge valve `S4,V

and `continue to force air lfrointhe upper into the lower compartment. .The air is discharged from` the lower compartmentof the bottom tank 10,'through the discharge 17 Iot pipe 11,v (bubbling `up through .the .water seal) by the action ot the water 'flowing into andy discharging `from saidk compartment,- `as described: ini connection with y=the illustra.- tion Fig. 2. f y

When the valve 34 of said lower compartment of thebottomftank is closed, the water overflowing into said compartment from the upper compartment of said tank, forces air from said lower compartment through perforations 28, pipe 11b, 11 and discharge 17` and this air discharge continues'until the water in the lower: compartment reaches and elevates float l50 and discharge valve 45 and thereafter continues even it the water in the lower compartment overflows through perforations 23 as air is thereby carried down pipes 11? 11, with the walter. When the water level in theupper compartment drops suiiiciently, the discharge valve 34 is opened, and the outrush of water through branch 28 and pipe 11, sucks out, entrains and-carries air which is discharged atl?.

The same body of water is thus used over and'over again` to successively produce air exhausting operations, thereby effecting economy in the use of municipal water, and at the same time an exceedingly efficient air exhausting system for heating plants is produced. V i

The air exhausting means as thus described, is adapted for use when the steam pressure in the radiators is less than atmospheric pressure and it is necessary to provide means for drawing air from the radiators. When, however, the radiator system is under pressure above that of the atmosphere, there is 11o-necessity of providing air exhausting means for the radiators as there is then no air leakage into the radiator system and the dead air will be forced into the air vpipe line. I therefore, provide means in lmy improved systemyior automatically discontinuing the filling and draining of the tanks to produce air exhausting suction, when the pressure in the radiator system is such as to make unnecessary theemployment of such suction, thus avoiding a great waste of water.

\ For this purpose, I preferably automatically cut oli" the flow of water through pipe 14 into the uppermost tank of the series, when pressine abo-ve atmospheric exists in the radiator system and in pipe 12. In the example illustrated, l provide the valve 15, in pipe 14, this valve being shown as comprising a casing having an inlet 55 from the source of liquid supply through pipe 14, and an outlet 56 communieatingwith the lower end ot pipe 14 which leads to the sup-` ply pipe of the uppermost tank;

The outlet 56l forms a valve seat, shown as a tapering seat, on which valve head 57 is arranged to be seated to stop the flow oi' water through said valve. The valve is operated by a lever, which is in turn actuated, to start or stop the flow of wateigby suitable pressure operated meansconnected with the radiator system. For` instance, a lever 58 is provided, extending outwardlyL from the valve casing through a lateral extension 59, and pivotally connected at its inner end to the valve stem 60 of valve head 57 as shown at 61. rlhe lever isshown as pivoted intermediate of its ends in the valve casing, as by providing a fiexible rubber cork 62, plugging' the end of extension59 so as to provide a leak proof connection for the valve casing, the cork being pierced byv the lever 58 and` forming the fulcrum therefor. i o

The means .tor actuating lever 58 to start or stop the tlow throughvalve 1F, is shown as a .flexible diaphragm 64, having a rod 65 lixed thereto and pivotally joined to lever 58 adjacent its outer end.

The diaphragm forms the flexible wallet y a pressure chamber 66 connected by air pipe ,67, to the radiator system, preferably through air line pipe 12. The extreme outer end of lever 58 is preferably provided with a counter weightS, which may beV adjustably positioned along the lever, to cause diaphragm 64 to elevate and close valve 15, and stop the iiow of water to tankl, when any predeterminedpressure in the radiator system is reached.l ln practice, the counter weight is usually adjusted to cause closing of valve 15 andthe shutting oil of the flow of water to the tanks, as soon` as pressure in the radiator system rises above atmospheric pressure, and to cause the yflow, of water to thetanks to start again as soon as the pressure drops below atmospheric. j

The system as above describedbeing in' in operation. When, however, as in mild weather, it is desirable to putoutof use certain of the radiators, it becomes necessary in the interest of economy and eficiency, to prevent the air exhausting action as above described upon the radiators which are not in use; since an even greater amount of energy would be expended in maintaining a vacuum in these radiators not in use, than would be expended if the latter were working. It is therefore essential to etlicient operation of the system, that when the steam to any radiator is sluit off, that the air valve 5 of said radiator also be closed, so that the air exhausting mechanism will not act upon the radiators not in use, but only upon the radiators in active use.

It will be found, however, that through carelessness, or neglect, the valve 6 will often be left open after valve 5 of a radiator has been closed, thereby continuing the air exhausting action upon said radiator and putting unnecessary work upon the vacuum creating means. I therefore have provided means for automatically closing the air outlet valve 6 of a radiator whenever the steam inlet valve 5 thereof is closed, and for reopening valve 6 as soon as valve 5 is reopened.

Any preferred mechanical means may be employed for causing this coaction between valves 5 and 6. In the present example, I have shown simple and efficient means wherein the valve 6 comprises a casing having a lateral extension forming the connection between the radiators and the valve casing. the air pipes 3 leading to the air pipe line 4, being connected to the ends of said casing.

A valve head 7l is provided in extension 70, arranged to seat therein to form a closure between the radiator and the air pipe line. The valve head may be actuated by a lever 72. to open or close said valve, the lever being shown as extending through the valve casing and pivoted therein, a suitable air tight joint 78 being provided at said pivot. Lever 72 is arranged to be operated so as to unseat valve head 71 and open valve 6, whenever valve 5 is opened. Then valve 5 includes a usual rotating valve stem 74. this may be accomplished b v a flexible connection shown as a cable 75. wound around valve stem 74 at one end and connected to lever 72 at its opposite end. and so arranged that opening movement of valve 5 will wind the cable upon valve stem 7 4, and pull lever 72 so as to open valve 6. When valve 5 is rotated in the opposite direction so as to close the same, and the pull of cable 75 upon lever 7 2 is released, the lever may be moved in the opposite direction so as to close valve 6, by a suitable spring 76.

The cable 7 5 preferably extends through the radiator and may be enclosed in a protective casing 77 shown as extending from valve 5 to lever 72, to prot-ect the cable from the effects of the heat of the radiator.

Claim is not made herein to the provision of cut-off valves for the outlets of the radiators to assure closing and opening of the radiator outlets when the radiator inlets are closed and opened, as such improvement is disclosed and claimed by my application tiled June 17, 1925, Serial No. 37828 for fluid heating apparatus or system.

It is evident that various changes, modifications and variations might be resorted to without departing from the spirit and scope of my invention and hence I do not wish to limit myself to the exact disclosure hereof, but consider myself entitled to all such variations and departures as involve the definitions of the following claims.

That I claim is l. Apparatus for maintaining negative pressure in advance of the heating fluid in fluid house heating systems comprising a closed liquid drainage passage, means for supplying liquid thereto, and means for automatically forming bodies of water at successive points along said passage and causing them to descend in succession therein so as to draw the air in said passage downwardly through the same behind said descending bodies of water to exert air exhausting action throughout the said passage, substantially as described.

2. In a fluid house heating system, apparatus for maintaining a vacuum in the system in front of the heating fluid therein, comprising a series of successive closed liquid chambers at different levels, means whereby air exhausting columns of liquid are caused to successively descend from chamber to chamber and drive the air in said chambers successively downward from chamber to chamber, and means for supplying liquid to the top chamber of the series.

8. Apparatus for exhausting dead air from fluid house heating systems comprising a drain pipe, and means for forming the same body of liquid into columns of liquid -to successively descend through said pipe, substantially as described.

Apparatus for maintaining negative pressure in the radiator systems of fluid heating plants, characterized by a series of chambers having air exhausting connections with each other and with the radiator system, a source of liquid supply, and a series of devices constructed and arranged for successively and automatically filling and draining liquid from said chambers for successively forcing air from and drawing air into said chambers, substantially as described.

5. In a fluid house heating system, in combination, radiators, and means for maintaining negative pressure pull on the radiators,

said means comprising a series of closed chambers at different levels each having an ofi'take and an inlet, the inlet of the uppenI most chamber being connected with said radiators, the oiftake of the lowermost chamber leading to the atmosphere, and the inlets of each of the chambers below the up-l permost chamber being connected with the ofltake of the nent upper chamber to exert minus pressure pull through said chambers upon said radiators, and connections for supplying water to the uppermost chamber and for successively filling and emptying said chambers into the next lower one and finally to the atmosphere through said inlets and ofltake, substantially as described.

6. Apparatus for maintaining minus pressure pull in a fluid heating system, comprising an air line having an air discharge to atmosphere, said air line including a vertical series of closed chambers each having an outlet communicating with the next lower chamber and finally with the atmosphere, means for supplying liquid for filling the uppermost chamber of said series, and for successively draining the liquid from said uppermost chamber through said outlet and successively filling and emptying the chambers below and finally discharging the water from the lowermost chamber at -said outlet' to atmosphere. y

In combination, an upper water compartment, a lower water compartment, a source of water supply for the upper compartment, an overflow connection for discharge of water from the upper part of' the upper compartment into the lower compartment, a drainage discharge from the upper compartment to the lower compartment, a valve controlling said discharge, means controlled by the water level in the lower compartment for opening` and closing said valve, an ofi'take from the upper part of the lower compartment, a drainage discharge from the lower compartment, and means for opening and closing said last named discharge controlled by the water in the upper compartment.

S. Apparatus for exerting negative pressure pull on the heating fluid in house heating systems, comprising` a series of liquid tanks at different levels, means to supply a charge of liquid to the upper tank, and air exhausting connections from each tank to the next upper tank and finally to the heating system forming drainage outlets from each tank to the next lower tank and finally to the atmosphere, said outlets being provided with automatic valve mechanism wherebyT the outlet is closed after the tank is drained and commences to refill, and is automatically opened after the tank is filled and has partially emptied to complete the drainage of said tank.

9. A tank arranged to be automatically successively filled and drained, an upper and lower compartn'ient, an air vent from the upper portion of said upper compartment to said lower compartment, said vent serv ring as an overflow from the upper to the lower compartment, a bottom discharge from the upper to the lower compartment, a valve for opening and closing said discharge provided with buoyant means in said lower compartment 'for unseating said valve when the overflow from the upper compartment has partially filled said rlower compartment, andmeans for draining saidlower compartment.

l0. A tank arranged to be automatically successively filled and drained, comprising upper and lower compartments, an overflow from said upper to said lower compartment, a discharge port from said upper to said lower compartment, a valve for automatically opening said port when the overflow from the upper compartment has partially filled the lower compartment, a drainage pipe from said lower compartment, and a valve for automatically closing said drainage pipe as the upper compartment is being filled, and for opening said drainage'pipe when said upper compartment has drained into the lower compartment.

ll. Apparatus for exerting negative pressure pull on the heating fluid ol' a heating system, comprising a series of tanks at different levels each having an upper and lower compartment, means for supplying liquid to the upper compartment of the uppermost tank, a Adrain pipe from each of saidl lower compartments to the upper compartment of the next lower tank and finally to the atmosphere, and means in each tank for auton'xatically draining` the upper comparu ment into the lower compartment when the overflow from the upper compartment has partially filled the lower compartment.

l2. Apparatus for exerting negative pressure pull on the heating fluid of a heating system, comprising a series of tanks at different levels, each having an upper and a lower compartment, means for sup Dlying liquid to the upper compartment of tlie uppermost tank, an overflow from the upper to the lower compartment of each tank, an overflow from each lower compartment to the upper compartment of the next lower tank and finally to the atmosphere, means in each tank for automatically draining the upper compartment into the lower com` partment when the overow from the former has partially filled the latter, and means for draining` each lower compartment into said overflow leading to the upper compartment of the ynext lower tank when said upper compartment has drained into said lower compartment.

13. Air exhausting` means comprising a vertically elongated closed combined air eX- hausting and liquid drainage passage havseries of tanks at different levels Connected ing a top liquid supply7 and a top cheek by combined air and liquid pipes to forni a 15 valve-controlled suction inlet, and having closed combined air exhausting and liquid a final bottoin Cheek-valve Controlled air drainage passage, the top tank having a 5 and liquid discharge, and means for causing ater suppl)T inlet. and an inlet through the liquid entering said passage at the top which air exhausting pull or suction is to toter-1n into successive air compressing and be maintained b v the action of the water 20 air exhausting bodies in Working by gravity passing dou'n through the passage Conduit? down through the passage by .stages to said each pipe arranged for the downward pasu discharge, Said passage being internally sage ot both air and liquid from tank to orined to provide down liowing streams of tank` the bottoni tank having a combined air liquid to prevent back How of air. and liquid discharge to atmosphere.

14. Air exhausting means comprising a WALTER S. HAVENv 

